Heat sink with radially arranged radiation fins

ABSTRACT

A heat sink includes a tubular base having longitudinal channels arranged in parallel around the periphery and a first and a second ribs protruding from the periphery and respectively extending along two opposite sides of each of the channels, and radiation fins radially arranged around the tubular base and supported on the second ribs, each radiation fin having an angled foot portion respectively inserted into the channels and secured thereto by the first ribs that are stamped down after the angled foot portions of the radiation fins are inserted into the channels of the tubular base.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to heat sinks and more particularly to a heat sink with radially arranged radiation fins for dissipating waste heat from a CPU, LED lamp or any other heat source, which comprises a tubular base having longitudinal channels and a longitudinal rib protruding from the periphery and extending along one side of each of the channels, and a plurality of radiation fins each having an angled foot portion that is inserted into one respective channel of the tubular base and fixedly secured thereto by means of stamping down the associated longitudinal rib.

(b) Description of the Prior Art

A conventional heat sink with radially arranged radiation fins has the radiation fins formed integral with the periphery of a tubular base and arranged around the periphery of the tubular base in a radial manner. The tubular base can be a round tube, rectangular tube, or a tube of any of a variety of configurations. Because the radiation fins and the tubular base are made in an integral piece, the fabrication of the heat sink is difficult, and the manufacturing cost is high. Further, a heat sink made in this manner is heavy and has low efficiency in heat dissipation. Therefore, such design of heat sink is not practical in application.

There is known a heat sink in which the radiation fins are bonded to the periphery of the tubular base by means of a soldering technique. Employing a soldering technique to bond radiation fins to a tubular base is not environmentally friendly. There are also heat sinks in which the tubular base has channels arranged around the periphery for the mounting of radiation fins. After insertion of radiation fins into the channels of the tubular base, the periphery of the tubular base are deformed to squeeze the two opposite sidewalls of each of the channels toward the two opposite sides of each of the radiation fins to secure the radiation fins in place. If the foot ends of the radiation fins are not fully inserted into the bottom of the channels or if an accidental vibration occurs when deforming the periphery of the tubular base, the radiation fins may be forced out of position or bent. When this problem happens, the radiation fins will not be kept in flush or firmly secured in position.

Accordingly, there is a need for a heat sink with radially arranged radiation fins that does not have the aforesaid problems.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. A heat sink in accordance with the present invention comprises a tubular base and a plurality of radiation fins arranged around the tubular base. The tubular base has a plurality of longitudinal channels arranged in parallel around the periphery thereof, and a plurality of first ribs protruding from the periphery and respectively extending along one side of each of the channels. Further, each radiation fin has an angled foot portion. The angled foot portions of the radiation fins are respectively inserted into the channels of the tubular base and secured thereto by the first ribs that are stamped down after the radiation fins are inserted into the channels of the tubular base. The angled foot portions of the radiation fins can be accurately inserted into the channels of the tubular base and closely attached to the bottom of each of the channels. Therefore, the radiation fins are firmly secured to the tubular base and kept in flush after the first ribs of the tubular base are stamped down.

Further, the tubular base has a plurality of second ribs protruding from the periphery and respectively extending along an opposite side of each of the channels opposite to the first ribs for supporting the radiation fins in position upon deformation of the first ribs.

Further, the radiation fins are respectively made of a thin metal sheet, each having an inner end edge folded up and curved to form the respective angled foot portion. Further, each radiation fin has an outer end edge folded up to form a respective outer obtuse edge opposite to the angled foot portion of the respective radiation fin. Further, the angle of the angled foot portions of the radiation fins can be 90-degrees, an acute angle or an obtuse angle.

Further, the tubular base can be a solid or hollow tube having a circular or rectangular cross section, or any of a variety of other configurations. For example, the tubular base can be made in the shape of a U-tube.

Further, the tubular base can be made by means of extrusion or stretch die stamping technology to form the desired channels, first ribs and second ribs on the periphery. The tubular base can be manufactured through a mass production process at a relatively low manufacturing cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a heat sink in accordance with a first embodiment of the present invention.

FIG. 2 is an oblique elevation of the heat sink in accordance with the first embodiment of the present invention.

FIG. 3 is an enlarged view of a part of FIG. 1, showing the radiation fins respectively inserted into the channels of the tubular base.

FIG. 4 corresponds to FIG. 3, showing a number of the first ribs stamped down.

FIG. 5 is an elevational view of a heat sink in accordance with a second embodiment of the present invention.

FIG. 6 is a bottom view of the heat sink in accordance with the second embodiment of the present invention.

FIG. 7 is an exploded view of the heat sink in accordance with the second embodiment of the present invention.

FIG. 8 illustrates the angled foot portions of the radiation fins respectively inserted into the channels of the tubular base before deformation of the first ribs.

FIG. 9 is an enlarged view of a part of FIG. 8.

FIG. 10 corresponds to FIG. 9, showing a number of the first ribs stamped down.

FIG. 11 is a schematic drawing of the present invention, showing the tubular base made in the form of a U-tube.

FIG. 12 is a schematic drawing of the present invention, showing the tubular base made in the form of a solid tube.

FIG. 13 is a schematic sectional view of the present invention, showing first ribs stamped down and forced into tight engagement with the 90-degrees angle of angled foot portions of the radiation fins.

FIG. 14 is a schematic sectional view of the present invention, showing first ribs stamped down and forced into tight engagement with the acute angle of angled foot portions of the radiation fins.

FIG. 15 is a schematic sectional view of the present invention, showing first ribs stamped down and forced into tight engagement with the obtuse angle of angled foot portions of the radiation fins.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIGS. 1 and 2, a heat sink in accordance with a first embodiment of the present invention comprises a tubular base 1 and a number of radiation fins 2.

The tubular base 1 has longitudinal channels 11 arranged in parallel around the periphery, and a first rib 12 protruding from the periphery and extending along one side of each channel 11.

The radiation fins 2 each have an angled foot portion 21 (see FIG. 3) insertable into the channels 11 of the tubular base 1 respectively.

During the assembly process of the heat sink, the angled foot portions 21 of the radiation fins 2 are inserted into the channels 11 of the tubular base 1 respectively, and then a stamping mold 3 is used (see FIG. 4) to stamp the first ribs 12 of the tubular base 1, deforming the first ribs 12 and forcing them into tight engagement with the angled foot portions 21 of the radiation fins 2 in the channels 11 of the tubular base 1 respectively. When assembled, the radiation fins 2 are firmly secured to the tubular base 1, and kept in a flush manner (see FIG. 1).

The radiation fins 2 are thin metal sheet members, each having an inner end edge folded up and curved to form a respective angled foot portion 21 and an outer end edge folded up to form a respective outer obtuse edge 22. The fold-up arrangement of the angled foot portion 21 enhances its engagement with the associated first rib 12. The fold-up arrangement of the outer obtuse edge 22 round the edges of the radiation fins 2 to avoid accidental injuries from sharp edges.

FIGS. 5˜7 show a heat sink in accordance with a second embodiment of the present invention. According to this second embodiment, the tubular base 1 has a first rib 12 protruding from the periphery and extending along one side of each of the channels 11 thereof, and a second rib 13 protruding from the periphery and extending along the other side of each of the channels 11 (see FIG. 8 or FIG. 9). After the radiation fins 2 are inserted into the channels 11 of the tubular base 1 and secured thereto by the first ribs 12, the second ribs 13 provide a support to the radiation fins 2 respectively (see FIG. 10), thereby holding the radiation fins 2 firmly in position without biasing. Thus, the radiation fins 2 are firmly secured to the periphery of the tubular base 1 irrespective of any possible vibration.

Further, in either of the aforesaid first or second embodiment, one or a number of retaining plates 23 may be attached to the radiation fins 2 at the top or bottom side to secure the radiation fins 2 together and to keep the radiation fins 2 properly spaced from one another.

According to the aforesaid first and second embodiments, the tubular base 1 has a circular cross section. In actual practice, the tubular base 1 can also have a rectangular, trapezoidal, oval or rhombic cross section, or any of a variety of other configurations. The tubular base 1 can also be made in the shape of a U-tube (see FIG. 11), having mounting through holes 141 on one closed side 14 thereof for mounting fastening devices (not shown) to affix the tubular base 1 to an electronic device or another heat source. In actual practice, the tubular base 1 can be formed of a solid tube (see FIG. 12), or a hollow tube.

FIGS. 13˜15 show different alternate forms of the angled foot portion 21 of each radiation fin 2. The angle of the angled foot portions 21 of the radiation fins 2 can be equal to, smaller than or greater than 90-degrees. In consequence, the foot portions of the channels 11 of the tubular base 1 are configured according to the angle of the angled foot portions 21 of the radiation fins 2. Further, the radiation fins 2 can have a relatively greater wall thickness (see FIGS. 13˜15). After the angled foot portions 21 of the radiation fins 2 are inserted into the channels 11 of the tubular base 1, the first ribs 12 are stamped down and forced into tight engagement with the angled foot portions 21 of the radiation fins 2, enabling the radiation fins 2 to be supported on the respective second ribs 13.

Further, as stated above, the tubular base 1 can be formed of a hollow or solid tube of any desired configuration and size. The tubular base 1 can be made by means of extrusion or stretch die stamping technology to form the desired channels 11, first ribs 12 and second ribs 13 on the periphery. The formation of the tubular base 1 can be done through a mass production process to lower the manufacturing cost.

In conclusion, the mounting arrangement between the tubular base and the radiation fins and structural features of the heat sink in accordance with the present invention are significant different from that of the prior art design. More particularly, the radiation fins can be inserted into the bottom side of the channels of the tubular base and fixedly secured thereto. After installation of the radiation fins in the tubular base, the radiation fins are kept in flush without biasing.

Prototypes of the heat sink have been constructed with the features illustrated in FIGS. 1˜15. The heat sink functions smoothly to provide all of the advantages disclosed earlier.

Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. 

1. A heat sink, comprising: a tubular base, said tubular base having a plurality of longitudinal channels arranged in parallel around the periphery thereof, and a plurality of first ribs protruding from the periphery and respectively extending along a first side of each of said channels; a plurality of radiation fins radially arranged around said tubular base, each said radiation fin having an angled foot portion, which is inserted into one said channel and secured thereto by the associated first rib upon deformation of the associated first rib by an external force.
 2. The heat sink as claimed in claim 1, wherein said radiation fins are respectively made of a thin metal sheet, each having an inner end edge folded up and curved to form the respective angled foot portion.
 3. The heat sink as claimed in claim 2, wherein each said radiation fin has an outer end edge folded up to form a respective outer obtuse edge opposite to the angled foot portion of the respective radiation fin.
 4. The heat sink as claimed in claim 1, wherein said tubular base further comprises a plurality of second ribs protruding from the periphery and respectively extending along a second side of each of said channels opposite to one said first rib.
 5. The heat sink as claimed in claim 1, further comprising at least one retaining plate attached to said radiation fins at one of top and bottom sides thereof to secure said radiation fins together.
 6. The heat sink as claimed in claim 1, wherein said tubular base has a round or oval cross section.
 7. The heat sink as claimed in claim 1, wherein said tubular base has a rectangular, trapezoidal or rhombic cross section.
 8. The heat sink as claimed in claim 1, wherein said tubular base is a hollow tube with a closed bottom side.
 9. The heat sink as claimed in claim 8, wherein said tubular base has a plurality of mounting holes on the closed bottom side thereof.
 10. The heat sink as claimed in claim 1, wherein said tubular base is a solid tube.
 11. The heat sink as claimed in claim 1, wherein said tubular base is a hollow tube.
 12. The heat sink as claimed in claim 1, wherein the angle of the angled foot portions of said radiation fins is 90-degrees.
 13. The heat sink as claimed in claim 1, wherein the angle of the angled foot portions of said radiation fins is an acute angle.
 14. The heat sink as claimed in claim 1, wherein the angle of the angled foot portions of said radiation fins is an obtuse angle. 